Loading...
Loading...
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Non-Standardized Food Allergenic Extract [EPC]
Dryopteris Filix-mas Root is a botanical substance primarily utilized as a non-standardized allergenic extract for diagnostic testing and immunotherapy, belonging to the class of plant-derived allergenic extracts.
Name
Dryopteris Filix-mas Root
Raw Name
DRYOPTERIS FILIX-MAS ROOT
Category
Non-Standardized Food Allergenic Extract [EPC]
Drug Count
22
Variant Count
24
Last Verified
February 17, 2026
About Dryopteris Filix-mas Root
Dryopteris Filix-mas Root is a botanical substance primarily utilized as a non-standardized allergenic extract for diagnostic testing and immunotherapy, belonging to the class of plant-derived allergenic extracts.
Detailed information about Dryopteris Filix-mas Root
This page is for informational purposes only and does not replace medical advice. Consult a qualified healthcare professional before using any medication containing Dryopteris Filix-mas Root.
Dryopteris Filix-mas Root, commonly known as Male Fern, is a botanical substance derived from the rhizome and roots of the Dryopteris filix-mas plant. In modern clinical practice, it is primarily classified as a Non-Standardized Plant Allergenic Extract [EPC]. Historically, this substance held a prominent place in pharmacopeias as an anthelmintic (a medication used to expel parasitic worms), specifically for the treatment of tapeworm infestations (cestodiasis). However, due to its significant toxicity profile and the development of safer synthetic alternatives like praziquantel and niclosamide, its use as an internal medication has largely been supplanted.
Under current FDA frameworks, Dryopteris Filix-mas Root extracts are utilized in the field of allergy and immunology. As a non-standardized allergenic extract, it is employed by healthcare providers to diagnose specific sensitivities in patients who may exhibit allergic reactions to fern spores or related botanical components. The extract contains a complex mixture of proteins, glycoproteins, and polysaccharides that can trigger an IgE-mediated response in sensitized individuals. According to the FDA’s Established Pharmacologic Class (EPC) indexing, it is also curiously associated with classifications such as Copper-containing Intrauterine Device [EPC], though its primary clinical relevance remains in the realm of allergenic extracts. This classification often stems from complex regulatory database mappings where specific botanical components are tracked across various medical device and drug categories.
The mechanism of action for Dryopteris Filix-mas Root depends entirely on its clinical application. When used as a diagnostic allergenic extract, the substance works by eliciting a Type I immediate hypersensitivity reaction. Upon introduction to the skin (via prick, puncture, or intradermal injection), the allergens in the extract bind to specific IgE antibodies previously fixed to the surface of mast cells and basophils. This binding causes the cross-linking of IgE receptors, leading to degranulation and the release of inflammatory mediators such as histamine, leukotrienes, and prostaglandins. This results in a visible "wheal and flare" reaction, which clinicians use to confirm an allergy.
From a historical and toxicological perspective, the "active" components of the root include phloroglucinol derivatives, collectively known as filicin or filicic acid (including albaspidin, aspidin, and desaspidin). At the molecular level, these compounds were believed to paralyze the muscles of parasitic worms, such as Taenia solium and Diphyllobothrium latum, by interfering with their neuromuscular transmission. However, in humans, these same compounds exhibit high affinity for the central nervous system and the gastrointestinal tract, leading to the severe toxicity that limits its modern internal use.
When administered topically or via skin-prick testing as an allergenic extract, systemic absorption of Dryopteris Filix-mas Root is negligible. This localized application is designed to minimize systemic exposure while maximizing the local immunological response. Historically, when taken orally as an oleoresin, absorption was highly variable and dangerously increased by the presence of fats or oils in the diet, which could lead to systemic poisoning.
There is limited data on the distribution of Male Fern components in humans. Animal studies suggest that filicic acid derivatives, if absorbed systemically, have a high volume of distribution and a tendency to concentrate in fatty tissues and the liver. There is significant evidence that these compounds can cross the blood-brain barrier, leading to neurotoxic effects.
The metabolic pathways for the phloroglucinol derivatives in Dryopteris Filix-mas are not well-characterized in modern literature. It is hypothesized that the liver undergoes glucuronidation to conjugate these phenolic compounds for excretion.
Elimination occurs primarily through the biliary and renal routes. In cases of historical oral administration, the half-life was noted to be relatively long, with toxic effects sometimes persisting for several days after a single large dose.
Dryopteris Filix-mas Root is typically available in the following forms for clinical use:
> Important: Only your healthcare provider can determine if Dryopteris Filix-mas Root is right for your specific condition. Diagnostic testing should only be performed in a facility equipped to handle systemic allergic reactions.
For adult patients, the standard dosage for diagnostic purposes involves the application of a small drop of the non-standardized extract (typically at a 1:10 or 1:20 weight/volume concentration) to the forearm or back. A sterile lancet is then used to prick the skin through the drop. A positive control (histamine) and a negative control (saline) are administered simultaneously for comparison. The reaction is typically read 15 to 20 minutes after application.
If skin prick tests are negative but a strong clinical suspicion of allergy remains, a more sensitive intradermal test may be performed. The dosage typically involves the injection of 0.02 mL to 0.05 mL of a highly diluted extract (e.g., 1:100 or 1:1000 w/v) into the dermis of the upper arm.
Dosage for immunotherapy is highly individualized. It begins with a very low dose (often 0.1 mL of a 1:10,000 dilution) and is gradually increased (escalation phase) until a maintenance dose is reached. This process must be overseen by an allergist-immunologist.
Dryopteris Filix-mas Root extracts are not specifically FDA-approved for use in pediatric populations for immunotherapy, though they may be used for diagnostic skin testing in children under the supervision of a pediatric allergist. Dosing for skin testing in children is generally the same as in adults (one prick per allergen), though the number of allergens tested in a single session may be limited to avoid excessive discomfort or systemic absorption.
No specific dosage adjustments are provided for renal impairment when the extract is used for diagnostic skin testing, as systemic absorption is minimal. However, patients with severe renal failure should be monitored for delayed clearance of any systemic mediators released during a reaction.
Similar to renal impairment, hepatic dysfunction does not typically require a dose adjustment for skin testing. However, the historical oral use of Male Fern was strictly contraindicated in patients with liver disease due to the hepatotoxic nature of filicic acid.
Elderly patients may have reduced skin reactivity (reduced mast cell density), which can lead to false-negative results. While the dose remains the same, clinicians must interpret results with caution and consider the patient's cardiovascular health, as they may be more vulnerable to the effects of epinephrine if a systemic reaction occurs.
Dryopteris Filix-mas Root extracts are administered exclusively by healthcare professionals in a clinical setting.
In the context of diagnostic testing, a missed appointment simply requires rescheduling. For patients on an immunotherapy schedule, a missed dose may require a "step-back" in dosage. If more than 2-4 weeks have passed since the last injection, the allergist will typically reduce the next dose to ensure safety and prevent a systemic reaction.
An overdose in the context of an allergenic extract usually manifests as an exaggerated systemic allergic reaction (anaphylaxis). Symptoms include:
In the event of an overdose/anaphylaxis:
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance.
The most frequent side effects of Dryopteris Filix-mas Root when used as an allergenic extract are localized to the site of administration. These are expected immunological responses rather than adverse toxic events.
> Warning: Stop taking Dryopteris Filix-mas Root and call your doctor immediately if you experience any of these.
When used correctly as a diagnostic tool or in controlled immunotherapy, there are no documented long-term adverse effects on organ systems. However, historical literature on the ingestion of Dryopteris Filix-mas Root (Male Fern) describes devastating long-term consequences:
There is no specific FDA Black Box Warning for Dryopteris Filix-mas Root itself; however, all Allergenic Extracts as a class carry a general warning regarding the risk of severe non-fatal and fatal systemic allergic reactions.
Summary of Class Warning:
Report any unusual symptoms to your healthcare provider.
Dryopteris Filix-mas Root extracts are intended for use by specialists in allergy and immunology. The most critical safety consideration is the potential for an immediate systemic allergic reaction. Patients must be screened for current health status before administration. For example, a patient experiencing an acute asthma flare-up should not undergo skin testing, as their threshold for a severe reaction is significantly lowered.
No FDA black box warnings for Dryopteris Filix-mas Root specifically, but it falls under the general class warning for Allergenic Extracts. This warning emphasizes that these products can cause anaphylaxis and must be administered in a clinical setting capable of managing such emergencies.
The risk of anaphylaxis is the primary concern. Patients with a history of high sensitivity to other botanical allergens or those with poorly controlled asthma are at the highest risk. Clinicians must have a standardized protocol for the administration of epinephrine and other emergency medications.
Patients with unstable angina, recent myocardial infarction, or severe hypertension may not be suitable candidates for skin testing or immunotherapy, as they may not tolerate the physiological stress of a systemic reaction or the administration of epinephrine used to treat such a reaction.
Standard skin testing does not typically affect the ability to drive or operate machinery. However, if a patient experiences a systemic reaction and is treated with antihistamines (which cause drowsiness) or epinephrine (which causes tremors and anxiety), they should not drive until the effects have completely worn off.
There is no direct interaction between alcohol and the diagnostic use of Dryopteris Filix-mas Root. However, alcohol can cause vasodilation and may theoretically increase the rate of allergen absorption or exacerbate the symptoms of a mild allergic reaction. It is generally advised to avoid alcohol on the day of allergy testing.
In the context of immunotherapy, discontinuation should be discussed with an allergist. Stopping suddenly does not cause withdrawal symptoms but will result in the loss of the immunological tolerance built up during the treatment, leading to a return of allergy symptoms.
> Important: Discuss all your medical conditions with your healthcare provider before starting Dryopteris Filix-mas Root.
There are no absolute drug-drug contraindications that prevent the use of Dryopteris Filix-mas Root extract for testing, but certain medications make the test results uninterpretable or make the treatment of a reaction dangerous:
For each major interaction, the management strategy is usually the temporary discontinuation of the interfering drug (under medical supervision) or the selection of an alternative diagnostic method like blood testing.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.
Dryopteris Filix-mas Root must NEVER be used in the following circumstances:
Patients who are allergic to Dryopteris Filix-mas Root may also show cross-reactivity with other members of the Dryopteridaceae family or other fern species (e.g., Pteridium aquilinum). There is also a theoretical risk of cross-sensitivity with certain mosses or other primitive vascular plants.
> Important: Your healthcare provider will evaluate your complete medical history before prescribing Dryopteris Filix-mas Root.
There are no adequate and well-controlled studies of Dryopteris Filix-mas Root extract in pregnant women. The primary risk during pregnancy is not the extract itself, but the potential for a systemic allergic reaction (anaphylaxis). Anaphylaxis in a pregnant woman can cause a sudden drop in maternal blood pressure, leading to uterine hypoperfusion and fetal hypoxia (lack of oxygen to the baby). For this reason, diagnostic skin testing and the initiation of immunotherapy are generally deferred until the postpartum period. Historical use of Male Fern as an anthelmintic was strictly contraindicated in pregnancy as it was thought to have abortifacient (abortion-inducing) properties.
It is not known whether the components of Dryopteris Filix-mas Root extract are excreted in human milk. Because systemic absorption from skin testing is minimal, it is generally considered unlikely to affect a nursing infant. However, caution should be exercised, and the decision to test should be based on clinical necessity.
Safety and effectiveness in children for immunotherapy have not been established. For diagnostic purposes, skin testing can be performed in children, but it must be done with caution. Children may be more prone to vasovagal reactions (fainting) and may find the procedure distressing. The number of skin tests performed at one time is usually reduced in younger children.
Clinical studies of allergenic extracts generally do not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently than younger subjects. In geriatric patients, the skin's reactivity to histamine and allergens decreases with age, which may result in smaller wheal sizes and a higher rate of false negatives. Additionally, older patients are more likely to have underlying cardiovascular disease, increasing the risk associated with a systemic reaction or the use of rescue epinephrine.
No dosage adjustment is required for skin testing. In the event of systemic toxicity (from ingestion), renal failure would significantly slow the clearance of toxic metabolites, necessitating intensive supportive care and potentially hemodialysis.
No dosage adjustment is required for skin testing. Historically, Male Fern was contraindicated in patients with liver disease because the phloroglucinol derivatives are processed by the liver and can cause further hepatic injury.
> Important: Special populations require individualized medical assessment.
As a diagnostic allergenic extract, Dryopteris Filix-mas Root works by providing a concentrated source of fern-specific antigens. When these antigens cross the skin barrier, they encounter IgE antibodies bound to the surface of cutaneous mast cells. The resulting cross-linking triggers the release of histamine and other mediators.
In its historical role as an anthelmintic, the mechanism involved the active principle filicic acid. Filicic acid acts as a vermifuge by paralyzing the helminth's suckers and musculature. This prevents the worm from maintaining its attachment to the intestinal wall, allowing it to be expelled by a subsequent saline purgative (like magnesium sulfate).
| Parameter | Value |
|---|---|
| Bioavailability | < 1% (Topical/Prick); High (Oral with fats) |
| Protein Binding | Unknown |
| Half-life | Not applicable for skin testing |
| Tmax | 15-20 minutes (local reaction) |
| Metabolism | Hepatic (minor systemic portion) |
| Excretion | Renal/Biliary |
Dryopteris Filix-mas Root is classified as a Non-Standardized Plant Allergenic Extract. It belongs to the broader therapeutic category of Allergenics, which includes both diagnostic and therapeutic (immunotherapy) products used in the management of IgE-mediated allergic diseases.
Medications containing this ingredient
Common questions about Dryopteris Filix-mas Root
In modern medicine, Dryopteris Filix-mas Root is primarily used as a diagnostic allergenic extract to identify if a person is allergic to certain types of ferns. Doctors use a liquid form of the root to perform skin prick tests, which help diagnose the cause of allergic rhinitis or asthma. Historically, it was used to treat tapeworm infections, but this is no longer common due to the risk of severe side effects. Today, its role is almost entirely limited to the field of allergy and immunology. It is never used for self-treatment of medical conditions.
The most common side effects are localized to the area where the skin test was performed. These include a raised, itchy bump called a wheal, redness (erythema), and a surrounding area of warmth or swelling. These symptoms usually appear within 15 minutes and disappear within a few hours. Some people may experience a delayed reaction where the area becomes swollen again several hours later. Systemic side effects like hives or sneezing are rare during diagnostic testing. Serious reactions are very uncommon but require immediate medical attention.
It is generally recommended to avoid alcohol on the day you are scheduled for allergy testing with Dryopteris Filix-mas Root. Alcohol can cause your blood vessels to dilate, which might theoretically increase the speed at which the allergen is absorbed or make a mild reaction feel more intense. Furthermore, alcohol can interfere with your ability to recognize early symptoms of a serious allergic reaction. If you have consumed alcohol, you should inform your allergist before the procedure begins. Always follow the specific pre-test instructions provided by your clinic.
Dryopteris Filix-mas Root is generally avoided during pregnancy unless the diagnostic information is absolutely essential. While the extract itself is unlikely to harm the fetus, the risk of a systemic allergic reaction (anaphylaxis) during the test poses a danger to the baby by reducing oxygen flow. Most healthcare providers will recommend waiting until after delivery to perform allergy skin testing. If you are pregnant or planning to become pregnant, discuss the risks and benefits with your allergist. Historical oral use of this root was strictly forbidden in pregnancy due to toxicity.
When used for allergy testing, the extract works very quickly, with results appearing in about 15 to 20 minutes. The healthcare provider will apply the extract and then check your skin for a reaction after a short waiting period. If you are receiving the extract as part of immunotherapy (allergy shots), it takes much longer to see a benefit. Most patients require several months of weekly injections before their allergy symptoms begin to decrease. The full effect of immunotherapy may not be reached for a year or more.
Since Dryopteris Filix-mas Root is typically administered as a one-time diagnostic test, there is no 'stopping' the medication. However, if you are receiving it as part of a long-term immunotherapy program, stopping suddenly will not cause physical withdrawal symptoms. Instead, your allergy symptoms will likely return because your body has not fully developed a tolerance to the allergen. If you need to stop your allergy shots, you should consult your doctor to discuss the best way to manage your allergies moving forward. Never restart shots after a long break without medical supervision.
If you miss an appointment for a diagnostic skin test, you can simply reschedule it for another time. If you miss a dose of your allergy immunotherapy (shots), you should contact your allergist's office immediately. Depending on how long it has been since your last injection, the doctor may need to reduce the dose for your next shot to ensure your safety. Missing multiple doses can increase the risk of having a reaction when you restart. It is important to stay as consistent as possible with your immunotherapy schedule.
There is no clinical evidence to suggest that Dryopteris Filix-mas Root causes weight gain. When used as an allergenic extract for skin testing or immunotherapy, the amount of the substance used is extremely small and does not affect the body's metabolism or appetite. It is not a hormone or a metabolic stimulant. If you experience unexpected weight gain while undergoing allergy treatment, it is likely due to other factors or medications, such as oral steroids. You should discuss any concerns about weight changes with your primary care physician.
Dryopteris Filix-mas Root can interact with several medications, particularly those used for allergies or heart conditions. Antihistamines, tricyclic antidepressants, and some heartburn medications can block the skin's reaction, leading to false-negative test results. More importantly, beta-blockers used for blood pressure can make it very difficult for doctors to treat you if you have a severe allergic reaction to the test. You must provide your doctor with a complete list of all medications you are taking before the test. They will tell you which ones need to be stopped and for how long.
Dryopteris Filix-mas Root is a botanical extract and is not marketed as a 'brand name' or 'generic' drug in the traditional sense. It is produced by various specialized laboratories that manufacture allergenic extracts for use by physicians. These extracts are often referred to by their common name, Male Fern Extract. Because it is a non-standardized product, extracts from different manufacturers may vary in their potency. Your allergist will select a high-quality extract from a reputable supplier for your diagnostic testing or treatment.